SYDNEY/WELLINGTON – A Virgin Australia pilot alerted Australian authorities about a live-fire drill by Chinese naval ships last week in the Tasman Sea that forced 49 flights to change their paths, Australia’s air traffic control agency head told a parliamentary committee.

Airlines including Qantas, Emirates, Air New Zealand and Virgin Australia modified flight paths on Friday after China warned them about a rare live-fire exercise in international waters between Australia and New Zealand.

Both countries have raised concerns with China saying they did not receive adequate notice from China’s navy about the military exercise off Australia’s New South Wales coast.

Pilots are frequently notified about military drills, rocket launches, and other concerns that may impair airspace via Notices to Airmen, or NOTAMs, which are usually filed at least 24 hours in advance of the event. Airservices Australia CEO Rob Sharp told a parliamentary hearing late on Monday that a Virgin Australia pilot warned his agency that the Chinese navy intended to conduct a firing rehearsal 300 nautical miles (483 kilometers) off Australia’s east coast. “So that was how we first found out about the issue,” he informed me.

The Chinese message was transmitted on an emergency radio channel mostly used by pilots and then communicated to air traffic control officials, forcing them to give an instant warning to commercial flights and establish an exclusion zone, according to Sharp’s deputy Peter Curran. The live-fire simulation may have begun approximately 30 minutes before the Virgin Australia pilot received the message, and Australia’s defence operations headquarters was notified 10 minutes after air traffic control received it, Curran said.

French defense forces, which conduct military drills in their Pacific islands, normally notify Australian air traffic 24 to 48 hours in advance, he said. Last week, a People’s Liberation Army Navy frigate, cruiser, and replenishment tanker entered Australian waters and traveled down the country’s east coast. On Sunday, China’s defence ministry stated that it had provided multiple safety notices in advance, that its activities were legal, and that they had no impact on aviation flight safety.

“Australian defence was absolutely informed, and I spoke with the chief of the defence force about what had happened. Albanese told reporters on Tuesday that Australia has had frigates monitoring the presence of these Chinese vessels both at sea and by air. The Australian defence department and the defence minister’s office did not immediately reply to a request for comment. On Tuesday, New Zealand’s military claimed the Chinese ships were 218 nautical miles east of Tasmania’s state capital, Hobart.